Balance control is the foundation of our ability to move and function independently. Various neurological diseases and injuries to the brain, spinal cord and other parts of the motor control system may lead to immobility loss of function and quality of life. With increasing age, the occurrence of clinical balance problems and the natural deterioration of balance function will increase the risk of balance loss and falls. In fact, falls are the leading cause of accidental death in the elderly population with over 11,000 deaths as a result of falls each year. Severe head injuries, hip and other fractures are common consequences of a fall that may lead to serious handicap. Every year some 350,000 hip fractures occur in the US of which more than 90 percent are the consequence of falls. Hip fractures are the leading fall-related injury that causes prolonged hospitalization and 25% of elderly persons who sustain a hip fracture die within six months of the injury. Hip fracture survivors experience a 10 to 15 percent decrease in life expectancy and a significant decline in overall quality of life. The scope of this problem is expected to grow as the number of elderly individuals will increase dramatically over the next 25 years.
Early mobilization following any injury or disease that leads to immobility is crucial for recovery and in the case of hip fractures, early ambulation has even been shown to be directly predictive of extended survival. Gait training using partial body weight support (BWS) is a neurorehabilitation technique that is becoming increasingly popular and is being used to enhance locomotor recovery following a range of motor disorders related to brain injury including stroke, spinal cord injury, cerebral palsy, Parkinson's disease as well as for early mobilization following total hip arthroplasty. However, improvement in balance function following BWS training only occurs in patients with minimal function prior to treatment suggesting that BWS training is not sufficiently challenging for more functional patients. Consequently, the challenge to the balance is either too small to stimulate improvement or is not sufficiently specific to balance function. Another issue associated with the BWS technique is that the harness supporting the subject decreases the need for natural automatic postural adjustments that are required for independent gait because the harness provides a lateral as well as vertical support. During gait the main site for an active control of balance is the step-to-step mediolateral placement of the foot. When supported by a harness the patient's mediolateral movement will be limited by a medially directed reaction force component that will help stabilize the body in the frontal plane and decrease or even eliminate the need for automatic postural adjustments that are required for independent gait. This restriction on automatic postural adjustments limits the full advantage of unloaded gait training.
Therefore, a need exists for a device that incorporates the principals of BWS but overcomes the problems associated with a harness that decreases the need for natural postural adjustments including mediolateral movements. There also exists a need for a device and method that provides unloaded gait training that allows automatic postural adjustments. There is also a need for a device and method that overcomes the aforementioned limitations that is completely mobile and therefore easily transportable into a patient's hospital room or placed in an outpatient clinic or in a patient's home, if necessary. The benefits of such a device would also extend to injured athletes to enhance their functional rehabilitation.